In 1984, Helwig was the first to describe aggressive digital papillary adenocarcinoma (ADPAca) as a rare variant of eccrine sweat gland carcinoma with the propensity to occur in male patients between the fifth and seventh decade. [1],[2],[3]

A 45-year-old male presented with a history of a mass on the left palm surface of the thenar eminence. The patient referred with an increase in size after one and a half years, the mass gradually became painful when pressure was applied. The mass was marginally excised. The pathologic examination revealed an ADPAca.

No suspicious signs were observed at the physical and radiological examinations. The patient underwent a wide local excision and sentinel node biopsy under local anesthesia. [4]

Lymphatic mapping was performed on the day before surgery. Radiopharmaceuticals were injected as a double aliquot of 7 MBq of 99mTc labeled nanocolloids (particle size < 80 nm) of human serum albumin (Nanocoll, Amersham Health, Milan, Italy) in 0.15 ml of volume, using a 25-gauge needle, intradermally, close to the scar.

After the radiocolloid injection, early and delayed static images of arm and thorax, in anterior and oblique anterior views, were obtained. Two hot spots were identified; the first one in the epitroclear basin of the left arm and the second one in the left axillary region [Figure - 1].

In the operation theater, 1 ml of patent blue was injected intradermally around the previous surgery scar area. After local anesthesia, a wide excision (WE) was performed with 1 cm margins and seven sentinel lymph nodes (SLNs) were identified and removed; six axillary and one epitroclear SLNs using a handheld gamma-detecting probe. The radioactivity in nodes was confirmed both intraoperatively and after removal.

The pathologic examination revealed that the skin and soft tissue margins were clear, and no metastatic lymph nodes were observed.

The patient started a regular follow-up in March 2006 consisting of clinical examination and loco regional ultrasound (US) evaluation every 4 months, with hepatic US and chest radiography performed once in a year. After 44 months on follow up, our patient is still disease free.

ADPAca is a rare neoplasm with the potential for local recurrence and distance metastases. The spread of metastases may occur via the blood or lymphatic routes. Bogner et al., in 2003 demonstrated the utility of SLN biopsy in detecting subclinical metastases of sweat gland carcinoma, which may occur in early treatment.[5] Currently, this neoplasm is classified as a malignant lesion grouping together adenocarcinomas and aggressive digital papillary adenomas. Low-grade neoplasm has local malignant potential and distant metastases have been described just in case of poorly differentiated lesion.

Histologically, aggressive behavior may be predicted by high cellular pattern with atypical cytology, mitoses and necrosis [Figure - 2] even tough these parameters are not consistently related to the outcome.

In literature, the use of SLN biopsy for aggressive digital papillary adenocarcinoma has been reported in only five cases, [4],[5],[6],[7] and just one was positive for lymph node metastasis.